#include<stdio.h>
int n,m,k,x;
struct sterg{int i,j;};
sterg v[100010];
int main()
{
FILE*f=fopen("stergeri.in","r");
FILE*g=fopen("stergeri.out","w");

fscanf (f,"%d %d %d",&n,&m,&k);
for (x=1;x<=m;x++) fscanf(f,"%d %d",&v[x].i,&v[x].j);
for (x=m;x>=1;x--) if (v[x].i<=k) k=k+v[x].j-v[x].i+1;

fprintf(g,"%d",k);
fclose(f);
fclose(g);
return 0;
}